Switching apparatus for electrically counting rapid reciprocating movements



April 4, 1939. R BLOMERlUs 2,152,4?

SWITCHING APPARATUS FOR ELECTRICALLY COUNTING RAPID REGIPROCATING MOVEMENTS Filed NOV. 26, 1937 Elf ' I71 VerzZar: Rae/ 5P0 Marius Patented Apr. 4, 1939 UNITED STATES PATENT, OFFICE 2,152,947 SWITCHING APPARATUS FOR ELECTRI-' CALLY ING MOVEMENTS COUNTING RAPID RECIPROCAT- Robert Blomerius, Berlin-Frohnau,. Germany, as-

signor to Rheinmetall-Borsig Aktiengeselb schaft, Dusseldorf, Germany,

Germany a corporation of Application November 26, 1937, Serial No. 17 6341 In Germany December 7, 1936.-

3 Claims. (01. 89-1)".

For coimting the number of shots fired by automatic guns, purely mechanical transmission mechanisms have not proved satisfactory. It has been demonstrated that with the high firing velocity of automatic guns, the action of such mechanical transmission mechanisms is too sluglize electrical means for operating counting de-- vices. In such attempts a contact was closed by a part of the gun which moved duringthe firing of a shot, and this'contact closed the operating circuit ofthe counter. This was not a practicable method because the time during which the contact was effective was much shorter than was necessary for the operation of the counter.

For this reason the present invention seeks to prolong the operative period in which the contact controlling the circuit is effective, in order that sufiicient time may be available for the moving gun part to transmit motion to the counter, said gun part moving in synchronism with the shot.

According to this invention when a shot is fired and when a part of a recoiling gun reaches its rear end position the circuits for both a lamp and a counting device will be closed. The circuits of the counter are however prevented from being restored to its normal inoperative condition during the return or forward movement of the gun part, by a locking device which latter is not released until the moving gun part has fully returned to its forward end position.

The accompanying drawing is a longitudinal section of a device, employed to count the shots fired in an automatic gun in accordance with the present invention.

A housing a, which is screwed on to the gun casing, contains impact levers b and b1 mounted in slots (11 and or. A pressure rod be is inserted in a longitudinal boring in the housing a and an extension bi of the rod projects into a boring or in aconnecting rod 0. The rod b: is biased to its position of rest by a compression spring be.

The connecting rod 0 has two notches or and 03 arranged one behind the other, with which notches a spring-pressed pawl or latch 04.00- operates. The rod 0 also carries a push member or abutment c5 of insulating material and is ses cured against rotation by a pin as which projects through a longitudinal slot co in the connecting rod.

Electrical contacts (21 and dz are mounted on an insulating member (1, carried on the housing a, and are electrically connected with insulated leads ds and (14.

In the longitudinal boring in the housing a, there is further. inserted a pressure rod e, of which an extension e1 projects into a boring in the connecting rod '0. The rod e is prevented .from rotating by a pin a4 projecting through a slot ea in the rod, and carries a push member or abutment ea of insulating material. The rod spring e; which the housing a.

Two flexible contacts f1 and f2 are mounted in an insulating member f on the housing a and are electrically connected with insulated leafs f3 and ii. The lead d: is connected with the lead is which connects with a terminal is, while the leads di and it connect with the terminals ds and f6 respectively. The terminals are preferably mounted in a junction box do. The. counting device g is inserted between the terminals is and f5, and a glow lamp 11 is connected across terminals f5 and fa, both being supplied with electrical energy by a source of current g2. The mode of operation is as follows:

At the end of the recoil, a projection V on.

the gun breech block impacts 'on contacts with the impact lever b1, which then pushes the rods e and c forwards. This causes the abutment member e3 to close contacts f1 and f2 and abutment member 05 to close contacts di and 112. Since the compression spring e4 returns the rod e into its rest position immediately it has been released by the lever in, the contacts fifz, on firing a; further shot, are'immediatelyopened and this occurs before the lamp 91 has time to glow. If, however, the breech projection V remains in its rear position against the lever in, this fact is indicated by the glow lamp g1 because its circuit remains closed by contacts 11 and fa. If, therefore, the lamp is not burning, the gunner knows that he must cock before firing.

The connecting rod 0 is held by the pawl or, which, on the forward movement of the rod e, moves out of the notch 02 into the notch ca. The contacts dl-dZ are, therefore, held closed by the abutment member 05 and remain closed until the projection V of the breech block rocks the lever b. This rocking of the lever b by the projection V causes the rod c to return, under the influence of the rod b3. into the position shown is biased to its position of rest by a compression in the drawing with the catch or engaging in the notch 02, thus breaking the contacts (Zr-d2. The time during which the circuit of the counter g is closed, is thus extended to the duration of the forward movement of the breech projection V, and is, therefore, suificient to advance the counter g by one unit.

A further contact can obviously be provided, which could indicate by the lighting of a lamp if the breech block rests in its forward position. This contact must be closed by the running of the projection V over the lever 17, and must be broken when the projection again releases the lever. I

I claim as my invention:

1. Switching apparatus for counting the strokes of rapidly reciprocating bodies and more particularly recoiling machine guns, comprising a lamp circuit and a counter circuit, separate contacts for each circuit and means for momentarily closing the lamp circuit when such body reaches the end of its recoil and simultaneously closing the counter circuit for the duration of the counter-recoil of said body, said means being actuated by said reciprocating body.

2. An apparatus according to claim 1, in which said circuit closing means consists of an axially movable actuating member provided with an abutment, for each of said contacts, a rocking lever exteriorly mounted adjacent to each end of said member and a projection on said re-' ciprocating body adapted to rock one of said levers respectively at each end of its reciprocating stroke, thereby displacing said member to make and break said contacts respectively.

3. An apparatus according to claim 1, in which said circuit closing means consists of an axially movable actuating member provided with an abutment for each of said contacts, a rocking lever exteriorly mounted adjacent to. each end of said member and a projection on said reciprocating body adapted to rock one of said levers respectively at each end of its reciprocating stroke, thereby displacingsaid member to make and break said contacts respectively, said actuating member consisting of three alined, interengaging rods, compression springs adapted to push the end rods against said levers and a spring latch adapted to retain the central one of said rods in and out of engagement respectively with the contacts in said counter circuit.

ROBERT BLOMERIUS. 

